<?php
function extra_enqueue_custom_styles() {
    wp_enqueue_style( 'extra-css', get_template_directory_uri() . '/extra/assets/extra.css', array(), '1.0', 'all' );
    wp_enqueue_script( 'extra-js', get_template_directory_uri() . '/extra/assets/extra.js', array(), '1.0', true );

    if(is_page('all-resources')) {
        wp_enqueue_style( 'bootstrap-5', 'https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.3.1/css/bootstrap.min.css', array(), '5.3.1', 'all');
    }
}
add_action( 'wp_enqueue_scripts', 'extra_enqueue_custom_styles' );